Soap API - woocommerce. Update price and Stock

I need a soap API for woocommerce. There is able to update Stock and price in my WooCommerce webshop. We already do have the API and plugin - but there is a bug, so not all product is update correct. Maybe this can be fix, instead of make a new plugin/API. The API do have to run as a cron job - every hour or 6 hours. For second we need to make a function, where it is possible to update the same thing, by using a CSV/xml file with "sku" (unik number), stock and price. So if the issue is, that's API don't work or skip, we can update manual. The plugin code have to update the quantity of the stock with these terms: - if the stock is below 0, change the stock status to 'out of stock' - if the stock is above 0, change the order status to 'in stock' within WooCommerce also on variable. - update the regular price (then I have a plugin, to calculate the sales price automatic) - BUT if the item isn't present or can be match, it have to be set to 0 and "out of stock" It is very importen - that speed don't gonna be hurt, while the shop is updating. The API provider got around 9000 products, but we only have about 3500 there need to be update. Some of the products are variable and some are simple but they should all have a SKU. If we can make a good price - and some good terms, we do have another project. We also need to make a API there automatic sync invoice from webshop to our finans program. So every time, a ordre is complete and woocommerce is makeing a invoice, it will automatic be sync into our finans program "Billy" - where it will be post on the different account, and the customer will be update as a new customer or as an old customer with a new bought. Hope to hear from you Regards Christian